1. Field of the Invention
A dual lumen catheter for use in hemodialysis treatment and the like.
2. Description of the Prior Art
Currently, there are three basic catheter configurations available for temporary hemodialysis. They are the coaxial configuration, the side-by-side configuration and the triple-lumen configuration in which a third smaller lumen for placement over a guide wire is located in the partition between the two blood transmission channels. All work well when they are maintained in a straight fashion. If they are bent accidentally or for tape-down purposes, blood flow is restricted, or worse, the catheters will kink and occlude. The invention herein described compensates for the need to curve a catheter by expanding the diameter of the lumens in the bend to neutralize the increased friction and turbulence which is created by the bend. Otherwise this friction and turbulence is translated into resistance to blood flow with increased pressure in the blood flow path. This catheter can be placed in either internal jugular or subclavian veins and still be secured to the relatively flat anterior chest wall. Taping in this location allows the patient to engage in normal activities without the catheter being noticed, becoming kinked or being inadvertantly dislodged.
U.S. Pat. No. 4,961,809 describes a dual lumen catheter for insertion into a vein of a patient for use in hemodialysis treatments having a first and second portion defining a shorter intake lumen and a longer return lumen respectively. The intake lumen is closed at the end and receives blood through at least one opening in the side wall of the catheter; while, the second lumen includes the second portion which is of smaller cross-section than the first portion.
U.S. Pat. No. 5,057,073 shows a dual lumen catheter for insertion into a vein of a patient for use in hemodialysis treatments having first and second portions defining a shorter intake lumen and a longer return lumen substantially identical to U.S. Pat. No. 4,961,809.
U.S. Pat. No. 4,895,561 teaches a dual lumen catheter assembly comprising a lumen 14 gradually changing from a D-shape at the tip 15 to a circular shape.
U.S. Pat. No. 4,692,141 describes a double lumen catheter having an elongated tube with a proximal first cylindrical portion having an internal divider to define a pair of discrete lumens including a shorter lumen opening at the distal end of the first cylindrical portion and a longer lumen opening at the distal end of the elongated tube where the return lumen 13 changes in cross-sectional area.
U.S. Pat. No. 4,990,133 shows a ureteral catheter stent including an elongated, relatively flexible, hollow tubular member having a plurality of drainage openings extending through a wall and having two end portions each being in the form of a hook and having at least one male and/or female interlocking unit formed into the end of at least one hook.
U.S. Pat. No. 4,493,696 teaches a double lumen cannula for hemodialysis comprising elongated flexible tubular members disposed one within the other for semi-permanent insertion into a central vein of a patient. Both members are sufficiently flexible to permit curving on a 12 cm radius without reduction in internal cross-section so as to avoid constriction of fluid flows.
Re. 31,873 describes a venous catheter device including a plurality of independent and noncommunicating fluid conveying lumens housed within or formed in a single catheter.
U.S. Pat. No. 5,053,023 shows a flexible dual lumen catheter for use in prolonged access including an elongated body having side-by-side lumens for receiving body fluid and other being a return lumen for leading fluid to the body.
U.S. Pat. No. 4,961,731 teaches a non-whip angiographic catheter having a preselected number of openings of preselected size, location and orientation along the straight portion of the catheter near the distal tip so as to distribute the force of the high-pressure dye injection jets while maintaining the non-whip characteristic.
U.S. Pat. No. 4,772,268 describes a dual lumen hemodialysis catheter including a tube having a circular external cross section rotatably received within a fitting. The fitting may be attached to the patient by sutures or the like and rotatably mounts the tube of the catheter. Stop means are provided on opposite sides of the fitting preventing the tube of the catheter from moving longitudinally relative to the fitting.
U.S. Pat. No. 4,626,240 shows a dual lumen central vein cannula for use in hemodialysis where the lumens are formed by a septum dividing an essentially circular tube longitudinally. A manifold at the proximal end of the tube separately distributes blood into the return lumen and collects blood from the inlet lumen.
Additional examples of the prior art are shown in U.S. Pat. No. 4,037,599; U.S. Pat. No. 4,134,402; U.S. Pat. No. 4,203,436; U.S. Pat. No. 4,583,968 and U.S. Pat. No. 4,682,978.